This invention relates generally to loudspeaker systems and more particularly to systems in which the audio frequency signal is divided into upper and lower ranges for higher fidelity reproduction from transducers particularly designed for that purpose. It is well known that the size, configuration and even the operating principles of high frequency acoustic transducers may differ substantially from those of low frequency transducers. Separate and independently operable transducers have been available for a long time, which can faithfully reproduce sound within given frequency bands. Efforts to reproduce high fidelity sound for the human ear have targeted questions such as where the frequency division should be made, how a transducer should function within its assigned frequency range, how many frequency divisions and transducers should be used, how the transducers should be physically arranged and associated with one another, and perhaps many other considerations of both broad and narrow scope.
It has been a practice for some time to provide speaker systems wherein the audio signal is divided into upper and lower frequencies and distributed to transducers particularly designed to best reproduce low or high frequency sound. It has also been common, for various reasons, to construct within a single assembly a combination of two or more transducers in which the high frequency transducer is co-axially mounted with respect to the low frequency transducer. The reasons and advantages of such co-axial relationship are well known and need no explanation here.
Co-axial loudspeakers have, in the past, employed entirely independent transducers, their interrelationship being almost entirely a matter of mechanical placement with some regard for the acoustical effects which result therefrom. Typically, "co-axial" speaker systems employ one or more high frequency drivers mounted above the lower frequency systems by a post or bridge-like support and have independent electrical connections; and as a result said drivers often have irregular frequency response characteristics due to phase cancellation between the drivers and deffraction effects caused by the support apparatus.